1. Field of the Invention
The present invention relates to the technical field of touch panels and, more particularly, to a high-sensitivity self-capacitance in-cell touch display panel device.
2. Description of Related Art
The conventional touch display panel includes a touch panel and a display unit overlapped with the touch panel. The touch panel is configured as an operation interface. The touch panel is transparent so that an image generated by the display unit can be viewed directly by a user without being sheltered by the touch panel. Such well known skill of the touch panel may increase additional weight and thickness of the touch display panel, and may further reduce the light penetration rate, and increase reflectance and haze of the touch display panel.
On-cell and in-cell touch technology were invented to overcome the drawbacks of traditional touch technology described above. The on-cell technology is to dispose a sensor on the back side of a color filter substrate to form a completed color filter substrate. One of the on-cell touch technologies is provided to dispose a touch sensor on a thin film and then bond the thin film onto the upper one of the two substrates. The in-cell technology is to dispose the sensor within the LCD cell structure. However, when the sensor is disposed within the LCD cell structure, the distance between the sensor and the common voltage layer is only several micro meters and thus the capacitance induced therebetween is greatly increased, such that, in comparison with such a large capacitance, the capacitance change caused by touch is too small to be detected. Furthermore, because of the short distance, the display signal may be seriously interfered, resulting in a had display quality.
FIG. 1 schematically illustrates the transparent electrode structure of a single-layer touch panel. As shown, there are a plurality of transparent electrodes 11 arranged in rows and columns, and the electrical signal sensed by one transparent electrode 11 is transmitted through a corresponding conductive wire 12 for output. Such a single-layer transparent electrode structure can realize an actual multi-touch detection. In use, the single-layer transparent electrode structure of FIG. 1 is combined with a display panel. However, when the single-layer transparent electrode structure is integrated with the display panel, there will be an obvious capacitance produced between the single-layer transparent electrode structure and a common voltage layer of the display panel, which may cause noises to be produced and thus lower the accuracy in detection the touch position. In order to solve the aforementioned problems for the in-cell touch panel, a direct solution is to partition the common voltage layer into several blocks for being operated with the display control in a time sharing manner, which not only restricts the resolution and size of the touch screen but also negatively influences the display quality and greatly increases the difficulties in designing and trimming of the display control circuit and manufacture of the panel, resulting in low production yield and high manufacturing cost. Therefore, it desired for the aforementioned in-cell touch display panel structure to be improved.